The invention relates to pressure seals between two structural members and a method for producing same.
Some machinery includes joints between components which require both a high pressure seal between the mating surfaces of the components and also a metal-to-metal contact between the mating surfaces. An example for such requirements is the joint between the cylinder block member and the crankcase member of a two-cycle internal combustion engine. These two members have machined recesses which, upon assembly of the members, cooperate to define crankshaft bearing bores. Any spacing between the mating surfaces can cause the bearing bores to be out of tolerance. It is generally undesirable to use a gasket as the pressure seal between the cylinder block member and the crankcase member because of the resultant dimensional effect on the bearing bores.
The most common approach for providing the pressure seal between these components has been to use an elastomeric sealing member which is compessed into a groove provided in one of the mating surfaces. While such a sealing arrangement generally is satisfactory, leakage can occur when there is crankcase flexure. The use of a layer of a sealant, such as a silicone rubber material, between the mating surfaces causes the same dimensional problems as the gasket. If the sealant layer is made very thin so as to minimize the effect on dimensional tolerances, relatively small crankcase flexures can cause tearing of the sealant and a resultant leakage.
Attention is directed to the following U.S. Pat. Nos.:
Snyder -- 1,348,667 issued Aug. 3, 1920 PA0 Gillette -- 2,062,305 issued Dec. 1, l936 PA0 Grawey et al -- 3,116,198 issued Dec. 31, 1963 PA0 Miklau et al -- 3,586,338 issued June 22, 197l